Grinding machine



Dec. 26, 1922. 1,440,148

H. W. HILL. GRmnmc Mncmuz. FILED MAR. 8, 1920- 4 SHEETSSHEET I INVENTOR mam w HILL ATTORNEYS H VI. HILL. Gnmomc Macrame. FILED MAR. B. 1920 4 SHEETS'SHEET 2 INVENTOR JEHREYWHLLL I ATTORNEYS H. W. HILL. Gmwnms Mncmus- FILED MAR. 8.

INVENTOR HARRYWHJLL ATTORNEYS a m L M HM W w H m R G Dec. 26, 1922.

4 SHEETS'SHEET 4 FILED MAR. 8. I920.

INVENTOR HARRY W HILL Patented Dec. 26, 1922.

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Application filed MareIi B, 19520. ierial No. 363,930.

ToaZZ whom it may concern: Be it knownthat I, HRRY W. HILL, a citizen of the United States, residing at Southbridge, in the countyof l Vorcester and State of Massachusetts, have invented certain new and useful Improvements in Grinding ll lachines of which the following is a specification.

This invention relates to improvements in grinding machines and has particular reference to an improved form of machine adapted for use in the production of ophthalmic lenses. I I a The leading Object of the present invention is the provision of :an improved and simplified construction of machine which shall facilitate the rapid and economical production of ophthalmic lenses.

A further. object of the present invention is the provision of a machine which shall possess the advantage over the prior art of requiring a less number of parts, have a sim plified construction and which shall be substantially automatic in operation, and shall rapidly and efliciently produce ophthalmic or other similar lenses, and which will enable a single machine to handle a much larger number of lenses in the case of strong curves at one operation than has hitherto been possible,

Other objects and advantages of my improved machine shouldbe readily apparent by reference to the following Fspe'cification taken in connection with the accompanying drawings, and it will be understood that I may make any modifications in the speclfic details of construction shown and described within the scope of the appended claims without departing from or exceeding the spirit of m invention.

Figure I represents a vertical sectional view through a machine embodying hey im- 'provements.

Figure 11 represents a similar view showing the parts shifted to a different position as occupied during the grinding operation.

Figure HI represents a side elevation of the machine.

Figure IV represents a front view of a,

spindle 2 driven as by the pulley 3 to cause the spindle to rotate. Theugper end of the spindle is preferably provided with acone or similar point 1 fitting in the socket 5 of the bowl lap 6 which is preferablysubstantially hemispherical in form, provided at its outer edge with the outwardly and upwardly er;- tending abrasive receiving flange rim having cooperating therewith the scraper S for directing the abrasive against the lenses to be ground. These lenses 9 are carried by the block 10 which may be of any ordinary construction as for instance a semi-spherical cast iron base portion with an outer pitch or adhesive coating 11 which serves a secure the lenses in place. Centrally secured tothe I bloclrlO is its spindle or arm 12ha-ving at its outer end'the socket 13 to receive the ball cllon the oscillatingpin 15 carried by the transversely shiftablearm 16. This arm 16 A. weight 19 mounted on the upper endo f the pin 15 serves to actuate the same in the direction of the lap 6h The cam 18 is preferably carried by the drive, shaft 21 which isfurther connected asby the belt 22 with the pulley 3 on thespindle 2. a

The operation of my improved machine will probably be best understood by reference to Figures 1 and H, from which it will be noted that the lap which is to form the desired curve upon the lenses 9 is retated with the spindle 2, while the lens block 10 fills up the major portion of the lap leaving the space as at the left which contains a considerable portion of abrasive such as emery or similar substance suspended in water whereby it is carried between the block and lap to suitably abrade the several lenses 9. It will be understood that as the containinglap is rotating at a fairly high rate of speedcentrifugal ac tion will tend to throw the abrasive outward toward the side of the bowl and into the space enclosed by the rim 7 where it will be met by the scraper member 8, which will interrupt the swirl of the material and shoot the same forward centrally against the lens block. Inasmuch as the connection between the spindle 12 and lens pin 15 is a ball and socket one, and since the friction is much greater at the upper side of the lens block than at the lower due to the difference in speed of the adjacent portions the block unduly remaining in stationary position a transverse oscillatory motion is applied to the pin 15 as by the cam 18 shifting the pin transversely and thus causing the block to slide around somewhat within the bowl bringing the upper edge higher or lower as the oscillation is in the one direction or the other and supplying extremely satisfactory break-up for the grinding operation.

It is to be understood that while have particularly described the parts of my inrention as disposed with the lap as the outer or concave member and the block as the inner orconvex member, if desired'thechar acter of the parts may be reversed in that the lenses may be carried on the interior "ofthe bowl and the member inserted within the bowl may be the lens grinding or polishing member in the event that contrageneric curves are to be formed on the lenses and it is to be understood that 1 con sider this adaptation of the parts as equivalent and both as falling within the scope of the appended claims.

I would further call particular attention to the shape of the upper portion of the grinding "lap, in that the flange rim 7 is at an angle so that abrasive material crowded up out of the lap during the grinding operation onto the shelf will, if influid form, have a tendency to flow back down into the central portion of the bowl, while" the upstanding outer rim flange 23 serves to absolutely stop any material crow'dedjup or thrown outward by centrifugal action,

thus affording a space receiving the abrasive material so that it may be satisfactorily engaged by the scraper to throw the same back centrally of the lap.

It will be understood; that in the interest of lightness andto make the lens blocks more readily handable, they are preferably hollow, as is indicated in Figure I, while to prevent the abrasive from being Wasted, filling up this hollow and making the block unduly heavy as well as unduly slimy and disagreeable to handle, I preferably slip over the spindle 12 the-light cap member 31 having the rim- 25 adapted to be sprung over the outer edge of the lens block and make a tight joint therewith, thus closing up'the hollow central space and keeping out the abrasive material therefrom.

I claim: v

1. In a lens grinding machine, the combination with a bowl member having an outwardly deflected angularly disposed fiangeat the upper edge thereof, and an upstanding rim encircling the flange, of a scraper supported adjacent the' bowl and arranged to contact the flange and aportion of thebowl. 1 v V 2. In a device of the character'described,

the combination with a hollow or bowl like grinding lap, of means for rotating the lap, an outwardly flaring rim formed CODtlIlnous with said lap and terminating in an upstanding edge, and a scraper having aportion depending within the bowl of the lap for engaging the operative wall thereof, and a portion in engagement with the flaring rim to remove and inwardly deflect abrasive thrown thereinto.

In testinion 1 whereof'l have aflixed in 

